Function append_usage_metadata

src/sessions/shared.rs:365–378

Inserts transcript-recorded token usage into message metadata under the `usage` key the savings dashboard reads. Probes each candidate value in order and keeps the first recognized counters object.

(
    map: &mut serde_json::Map<String, Value>,
    candidates: &[&Value],
)

/// `usage` key the savings dashboard reads. Probes each candidate value in
/// order and keeps the first recognized counters object.
pub(crate) fn append_usage_metadata(
    map: &mut serde_json::Map<String, Value>,
    candidates: &[&Value],
) {
    if map.contains_key("usage") {
        return;
    }
    if let Some(usage) = candidates
        .iter()
        .find_map(|value| usage_counters_from(value))
    {
        map.insert("usage".to_string(), usage);
    }
}

fn collect_tool_names(value: &Value, tools: &mut Vec<String>) {
    match value {